JPS61274806A - Drilling machine for reference hole in printed substrate - Google Patents

Abstract

PURPOSE:To machine a reference hole to be drilled correctly in the center of a copper mark, by actuating a servomotor to move a drill head, which provides an eddy current type position sensor, on the copper mark and detecting a boundary position while calculating the center position by a controller. CONSTITUTION:A drill head 14, providing an eddy current type position sensor 10 and a drill 12 to be arranged, is positioned in the upper of a printed substrate 30 and reciprocated in a direction X in the drawing through a table 18 by a servomotor 16. If the drill head passes on a copper mark 32, a machine, changing an output current detected by the sensor 10, stores coordinates of a boundary in a controller 24 by a pulse signal of the servomotor 16 to calculate the center coordinate position. Similarly the machine stores the coordinate position in a direction Y to be calculated by a signal from a servomotor 20. Next the machine, actuating the servomotors 16, 20 in accordance with coordinates adding to the above described coordinate position a space l between the drill 12 and the sensor 10 to be calculated, drills a reference hole in the center position of the copper mark.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a reference hole machining device for a printed circuit board.

(b) Conventional Technology Holes for wiring in printed circuit boards are generally formed by pressing using a mold. To position the printed circuit board relative to the mold, fit the guide pins of the mold into the reference holes of the printed circuit board. Therefore, the reference hole needs to be accurately provided at a predetermined position on the printed circuit board. For this,
A hole processing device is used that detects a copper mark previously provided on a printed circuit board and drills at the detected position. Conventionally, a position detector with a set of optical sensors has been used to detect copper marks on printed circuit boards. In other words, the copper mark placed at the position where the reference hole is to be machined has a different light reflection state from the other parts where the resist is placed, so this is detected by the optical sensor.
Detect the center position of the copper mark.

(c) Problems to be solved by the invention However, in the case of using an optical sensor as described above, if there is a positional shift between the copper mark and the resist, the center of the copper mark can be accurately detected. There is a problem in that it is difficult to detect the position. In other words, when a part of the outer periphery of the copper mark where no resist is provided on the printed circuit board is exposed due to a misalignment between the copper mark and the resist, the optical sensor detects the position including this part. The position detected by the optical sensor and the actual center position of the copper mark will not match. Further, the detection accuracy of the optical sensor is also reduced when rust occurs on the copper mark. Furthermore, in cases where paint is placed on copper marks and resists, the position cannot be detected using a single optical sensor method.The above-mentioned method also applies when using a method that uses a television camera to detect the position. Exactly the same problem occurs.

The present invention aims to solve the above-mentioned problems.

(d) Means for Solving the Problems The present invention attempts to solve the above problems by using an eddy current position sensor as a position detector.

(E) Effect The eddy current position sensor moves back and forth above the copper mark in one direction (for example, the X direction), and the copper mark in the X direction is detected from the change in current when the eddy current position sensor passes over the copper mark. Calculating the center position Next, the eddy current position sensor is moved back and forth in the Y direction perpendicular to the X direction, and the center position of the copper mark in the Y direction is similarly calculated. As a result, the center position of the copper mark is detected, and then the drill is moved to this center position to form the reference hole. The eddy current type position sensor detects the position of the copper mark by the change in eddy current when it passes over the copper mark, so it can accurately detect the position of the copper mark even if the resist is misaligned with the copper mark. The center position of the copper mark can be detected. Furthermore, the center position of the copper mark can be detected even when the copper mark is rusted or covered with paint or the like.

(F) Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5 of the accompanying drawings.

FIGS. 1 and 2 show an eddy current position sensor 10 and a drill 12, which illustrate a printed circuit board reference hole machining device according to the present invention.
The drill head 14, which is provided with the
is placed above. The operation of the servo motor 16 and the servo motor 20 is controlled by a controller 24, and signals corresponding to the rotational positions of the servo motor 16 and the servo motor 20, that is, the coordinates of the drill head 14 in the X direction and the Y direction, are transmitted to them. It is detected by a provided pulse detector, for example, and is input to the controller 24. A detection signal from the eddy current position sensor 10 is also input to the controller 24 .

Next, the operation of this embodiment will be explained. First, the eddy current position sensor lO is positioned approximately above the copper mark 32 on the printed circuit board 30 as shown in FIG.
Point) First, the servo motor 16 is operated to reciprocate the eddy current type position sensor 10 in the X direction as shown by the broken line in FIG. When moving to the right in FIG. 3 through point B, the output current detected by the eddy current position sensor 10 changes as shown in FIG. 4.

The coordinates indicated by the pulse signal from the servo motor 16 at the point where the current rises to a predetermined value (that is, this corresponds to point B) are stored in the controller 24. Also, point C
The output current of the eddy current position sensor 10 when moving to the left in FIG. 3 through the point C also changes as shown in FIG. 5, and the coordinate value C at point C is stored. The controller 24 performs the calculation of X=(b+c)/2, and this X indicates the coordinate of the center position of the copper mark 32 in the X direction.Then, the servo motor 20 is operated, and the eddy current The position sensor 10 is reciprocated in the Y direction, and the center position of the copper mark 32 in the Y direction is calculated by the same operation as above.

This means that the center position of the copper mark 32 has been detected.Then, the servo motor 16 and the servo motor 2
0 and move the drill 12 to this center position. That is, from the state where the eddy current type position sensor 10 coincides with the center position of the detected copper mark 32, the servo motor 16 is operated by the distance # between the eddy current type position sensor 10 and the drill 12, and the rad 14 is moved toward the drill. It will be in a state where it has been moved. As a result, the drill 12 matches the center position of the copper mark 32, and then the drill 12 is lowered to machine the reference hole. As a result, a reference hole is accurately formed in the center of the copper mark 32. Since the eddy current type position sensor 10 is of a type that detects the eddy current that changes depending on the presence of the copper mark 32, it can detect the center position of the copper mark 32 without being affected by the state of the resist on the printed circuit board 30. can be detected. Further, even if rust occurs on the copper mark 32, it will hardly be affected.Furthermore, even if the copper mark 32 is covered with paint etc., the center position of the copper mark 32 can be detected. is possible.

(g) As described in detail, according to the present invention, the center position of the copper mark on the printed circuit board is detected using an eddy current position sensor, so that the center position of the copper mark is always detected. Accurate detection becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a reference hole machining device for a printed circuit board according to the present invention, FIG. 2 is a view seen in the force direction of arrow II in FIG. 1,
FIG. 3 is a diagram showing the trajectory of the copper mark and the eddy current position sensor, and FIGS. 4 and 5 are diagrams showing changes in the output current of the eddy current position sensor. 10. Eddy current position sensor, 12. Drill,
3011・φ printed circuit board, 32...11 copper mark.

Claims (1)

[Claims] A reference for a printed circuit board in which a copper mark provided in advance on a printed circuit board is detected by a position detector, and a reference hole is automatically formed at the detected position to serve as a reference for positioning in subsequent processes. A reference hole machining device for a printed circuit board, characterized in that the hole machining device uses an eddy current position sensor as a position detector.